• The Korean Journal of Pesticide Science
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• v.14 no.3
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• pp.191-198
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• 2010

To predict and design of new potent insecticidal compounds, the two dimensional quantitative structure-activity relationships (2D-QSARs) and molecular hologram quantitative structure-activity relationships (HQSARs) between the various physicochemical parameters as descripters of N'-phenyl-N-methylformamidine analogues (1-22) and their insecticidal activity against the two spotted spider mite (Tetranychus urticae) were discussed quantitatively. From 2D-QSAR models (1 & 3), the width ($B_2$) of $R_3$-group as sterically factor and optimal total dipole moment (TDM=2.025D) of $R_4$-group were mainly influenced to increase the activity. Therefore, the activities were depend upon the $R_3$- and $R_4$-groups. Particularly, it is predicted that the activity of newly designed potent compound (PI; $EC_{50}$=0.516 ppm) by 2D-QSAR models (3) and HQSAR model F2 was about 34.3 fold higher than that of the commercialized insecticide, Amitraz ($EC_{50}$=17.7 ppm).

• Journal of Environmental Science International
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• v.25 no.4
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• pp.505-516
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• 2016

With the development of nanotechnology, nanomaterials are used in various fields. Therefore, the interest regarding the safety of nanomaterial use is increasing and much effort is diverted toward establishment of exposure assessment and management methods. Occupational exposure limits (OELs) are effectively used to protect the health of workers in various industrial workplaces. This study aimed to propose an OEL for domestic multi-walled carbon nanotubes (MWCNTs) based on animal inhalation toxicity test. Basic procedure for development of OELs was examined. For OEL estimation, epidemiological study and quantitative risk assessment are generally performed based on toxicity data. In addition, inhalation toxicity data-based no observed adverse effect level (NOAEL) and benchmark dose (BMD) are estimated to obtain the OEL. Three different estimation processes (NEDO in Japan, NIOSH in USA, and Baytubes in Germany) of OELs for carbon nanotubes (CNTs) were intensively reviewed. From the rat inhalation toxicity test for MWCNTs manufactured in Korea, a NOAEL of $0.98mg/m^3$ was derived. Using the simple equation for estimation of OEL suggested by NEDO, the OEL of $142{\mu}g/m^3$ was estimated for the MWCNT manufacturing workplace. Here, we used test rat and Korean human data and adopted 36 as an uncertainty factor. The OEL for MWCNT estimated in this work is higher than those ($2-80{\mu}g/m^3$) suggested by previous investigators. It may be greatly caused by different physicochemical properties of MWCNT and their dispersion method and test rat data. For setting of regulatory OELs in CNT workplaces, further epidemiological studies in addition to animal studies are needed. More advanced technical methods such as CNT dispersion in air and liquid should be also developed.

• Ocean and Polar Research
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• v.27 no.1
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• pp.15-24
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• 2005

In order to investigate the structures and dynamics of phytoplankton communities, each physicochemical environmental factor, species composition, standing crop, and dominant species were examined in the marine ranching ground of Tongyeong coastal waters from April to October, 2000. During the studies, mean water temperature and salinity were $18.8^{\circ}C$ and 33.1 psu, respectively. DO, SS and transparency varied from 5.43 to 11.39 mg/l, 14.6 to 32.4mg/l and 3.5 to 9.0m, respectively. Light intensities varied from 0.02 to $966{\mu}E/m^2/s$, which decreased with depth. $NH_4-N,\;NO_3-N,\;NO_2-N,\;PO_4-P,\;and\;SiO_2-Si$ were fluctuated from 0.059 to 0.332 mg/l, 0.040 to 0.800 mg/l, 0.001 to 0.468 mg/l, 2.3 to $143.0{\mu}g/l$, and 0.007 to 0.600 mg/l, respectively. chlorophyll a concentrations were fluctuated from 0.7 to $8.9{\mu}g/l$. Among 130 taxa of phytoplankton communities observed. diatoms occupied more than 81.54% of the total species, and the others were dinoflagellates and silicoflagellates. Phytoplankton standing crops ranged from $4.6{\times}10^4\;to\;2.6{\times}10^6cells/l$. In October, the standing crops were at bloom level showing more than $10^6cells/lat$ all stations. Dominant species changed by month and station. Leptocylindrus danicus occupied 59.84% in April and 22.03% in June. Pseudo-nitzschia pungens in August and Chaetoceros socialis and Skeletonema costatum in October were predominant species. In order to investigate factors influencing the total phytoplankton standing crops the correlations between the standing crops of diatoms, dinoflagellates, all phytoplanktons occurred and environmental factors were calculated using a multiple regression analysis. The coefficient of determination $(R^2)$ for total standing crops was 0.63 which explained 63% of variance and that of $R^2$ for diatom was 0.82. In statistical analysis, the results showed that the environmental factors influencing the size of the communities were predominantly water temperature, salinity and silicate.

• Journal of Life Science
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• v.25 no.1
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• pp.75-83
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• 2015

Curcuma longa L. (CL), a traditional medicinal plant, is well known as a functional food ingredient. The major component of CL is a curcumin of anthocyanin family that has multi-functions such as antimicrobial, anticancer, and antioxidant activity. In this study, fermented milk containing CL was prepared using a mixed strain culture (Bifidobacterium bifidus, Streptococcus thermophilus, Lactobacillus acidophilus), and its physicochemical properties were characterized. In addition, inflammatory cytokine-modulating effects of the fermented milk were also investigated. As regards the properties of fermented milk, the growth rate of lactic acid bacteria in fermented milk containing CL was found to be remarkably more rapid than control. During fermentation, caseins and whey proteins were observed to be partially hydrolyzed, and lactic acid and acetic acid were produced in larger amounts than in the control. The sensory score of fermented milk containing CL was lower than control, owing to its bitter taste and strong flavor. RAW 264.7 cells treated with CL fermented milk supernatant showed no cytotoxicity. Inflammatory cytokines such as tumor necrosis factor-alpha (TNF-${\alpha}$) and interleukin-6 (IL-6) were significantly produced by fermented milk with CL, compared to control. The secretion of nitric oxide (NO) from RAW 264.7 cells significantly increased relative to the control. Results from the present study suggested that CL could be used as a natural immunomodulating ingredient for making yogurts, beverages, and other products.

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.609-614
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• 2007

This study aimed to evaluate the physicochemical and sensory properties of the cookies that were prepared with different concentrations [0, 0.5, 1, 2, 4, and 6 % (w/w)]. The pH of the cookie dough increased significantly at all garlic juice concentrations greater than 1%. The highest dough density value was 1.23, which occurred in the 2% added group; however there was no remarkable differences among the test groups. The spread factor of the cookies showed an inverse relationship with the garlic juice concentration as compared to the control group (10.63). Hardness decreased with increasing garlic juice concentration at levels greater than 1%, and it ranged from 1857.92 to 1695.02. In addition, the L-value decreased with increasing garlic juice concentration, while the a-value gradually increased. In the case of the b-value, however, no significant difference was found compared to that of the control group. In the sensory evaluation, the color of the cookies (3.44-5.11) increased dose dependently with the garlic juice concentration. Taste scores were higher with garlic juice additions over 2%; whereas flavor was considerably greater compared to that of control group. The overall acceptability of the garlic juice cookies was higher than that of the control group. From this investigation, the optimal concentrations of added garlic juice for improvements in cookie quality were found in the range of 1-2%.

• Food Science and Preservation
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• v.9 no.1
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• pp.19-27
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• 2002

The effect of gamma irradiation was investigated on the microbiological and physicochemical qualities of boiled-dried anchovies (large- and smallsized) packed in PVC film (0.06 ㎜) during storage at 15$\pm$1$\^{C}$ for 6 months. On the other hand, thermoluminescence characteristics of minerals extracted from the sample were analyzed to evaluate its possibility in detecting the irradiated anchovies. The samples were contaminated by microbial levels of 104∼106 CFU/g in total aerobic bacterial counts and negative in coliforms, which were different depending on the sample sizes. Gamma irradiation at 3 kGy was effective for improving the hygienic quality of both samples for 6 months, keeping the microbial population less than 20 CFU/g. Besides it was not detrimental to the quality attributes, such as instrumental color parameters L, a, b, ΔE), browning, TBA value, volatile basic nitrogen, trimethylamine-N and sensory properties(appearance, color, odor, tape, overall acceptability). However, storage conditions (time, temperature, packing) showed a critical factor nfluencing the quality changes of dried anchovies. Thermoluminscence analysis was prove to distinguish irradiated from non-irradiated anchovies by comparing both temperature at which glow curves appear and the curve intensity, that was possible even after 6 months at - 20$\^{C}$.

• Food Science and Preservation
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• v.20 no.4
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• pp.539-545
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• 2013

Effects of RS4 type resistant corn starch on the quality characteristics of cookies were investigated by physicochemical, instrumental and sensory evaluation. The resistant starch was made by cross-linking of corn starch as following; corn starch slurry was annealed at pH 2.0 and $50^{\circ}C$ for 2 h followed by the cross-linking reaction. The cross-linking reaction was performed at $50^{\circ}C$ for 12 h in the presence of 1.2%/st.ds NaOH, 10%/st.ds sodium sulfate and 10%/st.ds of sodium trimetaphosphate (STMP)/sodium tripolyphosphate (STPP) mixture. Dietary fiber content of the resistant starch was estimated to be 73.8% by the AOAC method. For quality characteristics, dough pH decreased with the increase of the resistant starch content and spread factor decreased a little at 20% of the resistant starch. The moisture content and L value of cookies increased with the increase of the resistant starch content. However, the hardness and fracturability decreased with the increase of the resistant starch content. In the sensory evaluation, no significant differences were observed between the two cookies with or without the resistant starch. The results of this study suggest that the RS4 type resistant corn starch can be a good ingredient to increase dietary fiber content in cookies without changes of their qualities.

• Polymer(Korea)
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• v.37 no.6
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• pp.702-710
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• 2013

Zaltoprofen loaded polyoxalate (POX) microspheres were prepared by an emulsion solvent-evaporation/extraction method like oil-in-water (O/W) for sustained release of zaltoprofen. The influence of several preparation parameters such as fabrication temperature, stirring speed, intensity of the sonication, initial drug ratio, molecular weight ($M_w$) of POX, concentration of POX and concentration of emulsifier has been investigated on the zaltoprofen release profiles. Physicochemical properties and morphology of zaltoprofen loaded POX microspheres were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimeter (DSC) and Fourier transform infrared (FTIR). Through the analyzed results, it was demonstrated that the characteristics of the microspheres greatly affected by the prepared condition. The releases behavior of zaltoprofen was investigated for 10 days in vitro. It was confirmed that the release behavior of zaltoprofen can be controlled by the manufacturing factor of solvent-evaporation/extraction method.

• Food Engineering Progress
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• v.22 no.4
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• pp.366-373
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• 2018

The rate of salt and sugar into pickled cabbages was determined, and physicochemical characteristics, such as sensory, texture, and pH, of vinegar pickled cabbages during storage were examined at different storage temperatures and vinegar concentrations. The rate of salt and sugar penetration was faster in smaller size and on leaves rather than the stem of cabbage. Also, higher salt and sugar concentration and higher storage temperatures led to increase in salt and sugar permeation rate. As a result of sensory test, lower storage temperature is the most suitable, and 6% vinegar concentration was the mostly appropriate. Hardness and cohesiveness were decreased significantly at the initial $1^{st}$ week storage time, but storage temperature did not show any significant effect. Addition of vinegar contents enhanced the hardness, but decreased cohesiveness. The pH was lowered with increasing vinegar content, indicated most significant factor on pickled cabbage. In general, salt and sugar contents rather than storage temperature have greater influence on permeation rate, and especially, addition of vinegar affects the texture of pickled cabbage.

• Journal of Food Hygiene and Safety
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• v.35 no.6
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• pp.521-534
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• 2020

Paralytic shellfish poisoning (PSP) occurs when saxitoxin (STX), which is produced by harmful algae (dinoflagellates) and then accumulated in bivalve shellfish by filter-feeding, is consumed by humans. With recent advances in analysis technology, it has been reported that dinoflagellates also produce a variety of analogues such as the gonyautoxin (GTX) group and the N-sulfo-carbamoyl toxin (C toxin) group, in addition to STX. Accordingly, CODEX and the EFSA are stepping forward to manage STX and analogues as STX groups requiring safety management. In Korea, the occurrence of dinoflagellates producing STX analogues has already been reported, and contamination of analogues (GTX group, C toxin group) in live mussels has also been reported. In this study, in order to provide the basis for systematic monitoring and safety management of STX and analogues, their physicochemical characteristics, occurrence of dinoflagellates, toxicity and toxic equivalency factor, analytical method and occurrence were widely reviewed. This review is expected to contribute to strengthening the safety management of STX and its analogues.